Mobs cast shadow through slab

I don't know if this occurs in other versions, but I noticed that my new llama's shadow cast down through the sandstone slab it was on to the sand beneath. Url below is a video clip showing this.

https://1drv.ms/v/s!Apr73Jy6zWsqsmjPu3IWMZdUdvNu?e=QxCaE7